This invention relates to internal combustion engines and, more particularly, to fuel delivery devices for such engines.
Internal combustion engines are widely used in industry and for providing motive power for many of the transportation devices utilized in developed societies, such as automobiles, trucks, farm machinery, and other vehicles. Most such engines use hydrocarbon fuels, such as gasoline, to supply energy for their operation. Because of the increasing awareness that the hydrocarbon resources of the world are depleting, it has become increasingly necessary to improve the operation of such power plants to provide the most efficient use of fuel possible. In addition, increasing concern has developed with respect to the environmental consequences of energy producing systems. Because of this concern, the polluting byproducts of the internal combustion process must be minimized in order to preserve the environment and the health of its inhabitants.
The operation of an internal combustion engine may be conveniently described by reference to the operating steps utilized in a typical four-stroke automobile engine which runs on gasoline fuel. In such an engine, the first stroke is the intake stroke, in which the piston is drawn downwardly in the cylinder by the momentum of the engine. This downstroke creates a partial vacuum, which draws an air and fuel mixture into the combustion chamber through the intake manifold and the carburetor. In the compression stroke, the piston is forced upwards, causing the air and fuel mixture in the combustion chamber to be compressed, increasing its pressure and temperature. At the end of the compression stroke, the mixture is ignited by a spark plug in the power stroke, and the resulting increase in pressure caused by the burning air and fuel mixture forces the piston down, transferring the energy of combustion into rotary motion through the connection between the piston and the crankshaft. Finally, in the exhaust stroke, the remaining byproducts of the combustion process are forced out of the combustion chamber and exhausted from the engine.
The carburetor, which is used in typical internal combustion engine designs, performs an important function in the intake stroke of the engine. The carburetor is provided to supply a suitable combustible mixture for the engine by combining intake air and liquid gasoline in the correct proportions. In order to perform this function, the operation of the carburetor depends on the partial vacuum which is created during the intake stroke of the engine. This partial vacuum draws outside air into the throat of the carburetor. Within the carburetor throat are located metering jets connected to a fuel chamber which contains a quantity of gasoline. The partial vacuum, aided by a venturi within the carburetor, causes fuel to be drawn out of the metering jets and sprayed into the incoming air stream. This fuel and air mixture is then drawn out of the carburetor, through the intake manifold, and into the combustion chambers of the engine, where it is ignited during the ignition stroke.
Ideally, the fuel in the mixture which is provided to the engine should be completely vaporized to achieve the best possible combustion during the ignition cycle of the engine. Due to the design of carburetors known in the art, however, the fuel in this mixture is only partially vaporized when it leaves the carburetor and enters the combustion chambers. This partial vaporization achieved in typical carburetor systems is believed to be detrimental to the optimum performance of the engine in terms of the efficient and pollution free operation of that engine.
An engine which is supplied with a partially vaporized mixture is believed to run less efficiently than when the mixture is completely vaporized, resulting in less than the optimum gasoline mileage which might be obtained. In addition, the inefficient combustion which is believed to be caused in an engine when the fuel mixture is not completely vaporized may also result in excessive byproducts of the combustion process being exhausted from the engine, resulting in greater quantities of pollutants being released into the environment by the engine. Numerous other undesirable operating characteristics of an internal combustion engine are believed to be caused or aggravated by the operation of such an engine with a fuel and air mixture which is only partially vaporized, as in the operation of a conventional carburetor. Such other problems may include rough running of the engine, carbon buildup within the engine, dilution of the engine lubricating oil by liquid fuel running down the walls of the cylinders, excessive operating temperatures, engine stall, engine flood-out, and poor starting in cold weather conditions. Because of these limitations and others discussed above, which are caused by the carburetion systems known in the prior art, there has developed a need for a fuel preparation and delivery system which will provide an improved fuel mixture for internal combustion engines and enable such engines to operate more efficiently and with less polluting byproducts of combustion.
More specifically, it would be advantageous to provide such a fuel delivery system which is capable of producing a more completely vaporized fuel mixture which will significantly increase efficiency and reduce undesirable byproducts.
Additionally, it would be advantageous to provide a more efficient fuel delivery system for internal combustion engines which may be readily adapted to a wide variety of presently existing engine types and sizes.
It would also be advantageous to provide an improved fuel delivery system for internal combustion engines which is relatively simple and trouble free in operation.